The city of Birmingham experienced a dramatic 12.6 percent drop in population over the last decade, losing 30,583 residents, according to the results of the 2010 U.S. Census released Thursday.

If population trends continue, Birmingham, with 212,237 residents in 2010, could become Alabama's second-largest city in 2012, falling behind Montgomery. The state capital had a population of 205,764 in 2010, but grew at a pace of about 420 people a year over the previous decade.

By 2017, if those trends continue, Birmingham would trail Mobile and Huntsville in population as well.

Birmingham's decline was offset in the metro area by rapid growth in places such as Hoover, which grew 30 percent, and Shelby County, which had the highest growth rate in the state at 36 percent. The Birmingham-Hoover metro area grew, remaining by far the largest in the state, topping 1.1 million people living in the seven-county area.

Birmingham Mayor William Bell said he was disappointed but not surprised by the numbers. He said it underscores the work that must be done to preserve the city's standing.

"It does mean our work is cut out for us," Bell said. "The city of Birmingham's goal is to attract individuals and corporations by working to improve the city's infrastructure, transit, parks and other amenities. We have to set our focus on improving the city's school system and preparing our next generation of leaders to stay in Birmingham and help grow the city."

Populations in Jefferson and Walker counties dropped by more than 3,500 people each. But in percentage terms, Jefferson's drop was slight, 0.5 percent. Jefferson County is still by far the state's most populous county with 658,466 residents.

Overall the seven-county metro area gained 7 percent. Shelby added 51,792 people, growing 36 percent during the past decade. Now with a population of 195,085, Shelby County has passed Tuscaloosa County to become the fifth-largest county in the state. St. Clair County gained 18,851 people, 29 percent. That's enough to make St. Clair the third-fastest-growing county, behind Shelby and Baldwin.

Among cities, Hoover was second only to Huntsville in terms of the number of new residents, adding 18,877 and reaching a population of 81,619 percent.

Hoover Mayor Tony Petelos said he was not surprised. "We continue to sell new housing permits," Petelos said. "Hoover is a great place to live and raise a family and has one of the better school systems in the state."

Brett Isom, a demographer with the Regional Planning Commission of Greater Birmingham, said the Census numbers continue a trend, with the older industrial communities of Jones Valley losing population, while communities south of Red Mountain experience gains. Trussville in the east and Gardendale and Fultondale to the north also experienced strong growth.

The three fastest-growing cities in the state among those that started the decade with populations of more than 10,000 were Helena, Trussville and Pelham. Vestavia Hills and Alabaster also ranked in the top 10, while Hoover and Gardendale also made it into the top 20.

Mountain Brook lost almost 1 percent of its population, and Homewood remained flat, growing by 124 residents.

Communities that were tiny a decade ago, like Calera and Chelsea, saw their population explode during the period, Calera's rising from 3,158 in 2000 to 11,620 and Chelsea's from 2,949 residents in 2000 to 10,183 in 2010.

St. Clair County is now the 15th most populous county in Alabama with 83,593 people.

"That is pushing 3 percent a year in growth for 10 years," said Stan Batemon, chairman of the St. Clair County Commission. "We are excited about it and also challenged by it."

Batemon said the economic downturn slowed growth in the past two years, giving the county time to catch up on expanding roads and infrastructure to meet new demands.

"I know the economic downturn has been hard on many people, particularly the unemployed," he said. "But for us, it gave us a chance to catch our breath and catch up on major projects."

Among other projects, the county officials kept applying pressure at the state and federal level to expand Interstate 20 to six lanes from Birmingham to Pell City.

"The highway was just overwhelmed with traffic from the growth and very dangerous," Batemon said.

The 2010 Census also pointed to shifting racial demographics in the metro area. White population declined 11,199 in Birmingham, but the black population loss was greater, dropping 22,581.

In unincorporated Forestdale, a white population of 5,556 in 2000 was cut in half 10 years later.

The white population also fell in Bessemer, Hueytown, Homewood, Fairfield, Mountain Brook and Jasper.

Black population rose in most of the suburbs.

Only in Birmingham, Fairfield, Bessemer and Jasper did black population fall. Hoover, Hueytown and Alabaster experienced the biggest increases in black population.

The Birmingham-Hoover metro Hispanic population increased 161 percent, with 48,530 Hispanics living in the seven counties in 2010.